Coaxial network (CATV) is a commercial term for the technology of the transfer of image and data by cable. The original intention of cable television was to provide a TV signal where, for certain reasons (for example, geographical), air signal could not be received. Originally coaxial cables were used for the signal distribution, replaced with optical cables in the course of the related technological development. Traditional cable television used exclusively analogue signal for its data transmission. Over time, continuous digitalisation has taken place, enabling the provision of more TC programs in compressed format and improved quality. The technology further permits digital data transfer, telephoning or VoD (Video on Demand). Today´s CATV distribution systems are mostly bidirectional and distribution uses the HFC hybrid fibre-coaxial network, i.e. a combination of optical cabling (for the trunk sections of the system) and coaxial cabling (branches to individual households). These networks are used for triple-play services, currently widely discussed, demanded and extending the client base. The product is a package of three services - data, voice and video. The classic data service (www, files etc.) is extended with real-time multimedia voice (VoIP) and video (IPTV/RF) service.